Clamp.



' UNITED STATES rATnNT OFFICE.

DAVID A. DUCI-IARME, OF FITCI-IBURG, MASSACHUSETTS.

CLAMP.

Specification of Letters Patent. Patented NOV. 30, 1909. Applicationfiled October 19, 1908. Serial No. 458,397.

To all whom it may concern:

Be it known that I, DAVID A. DUoHARMn, a citizen of the United States,and a resident of Fitchburg, in the county of Worcester and Commonwealthof Massachusetts, have invented a certain new and useful Improved Clamp,of which the following-is a specification.

The object of this invention is the construction of a clamp which willtake in work having non-parallel opposite faces; in which one membershall clear of all obstructions and will therefore permit of the clampand its work being laid flat upon a supporting surface, and which willcontain other improvements in details of construction hereinafter setforth. 1

Referring to the drawings forming part of this specification, Figure 1is a side View mainly in section, of a clamp embodying my improvements.Fig. 2 is a sectional view of the same on the line XX in Fig. 1. Fig. 3is a sectional View on the line YY in Fig. 1. Fig. 1 is a horizontalsection of a part of the upper jaw on the line ZZ in Fig. 1.

The reference numeral 1 designates what I term the upper jaw of theclamp, and 2, the lower jaw. At approximately midlength of these jawsare the slots 3 and 4:; the same being comparatively narrow andextending longitudinally of the jaws, as indicated by the dotted linesin Fig. 4, but much longer at the inner faces of the jaws than the outerones, as shown in Fig. 1.

In the slot 1 is pivoted the unthreaded end of the bolt or screw 5, thepivotal point 6 being at the small end of the slot. This bolt risesthrough the-slot 3 and is provided with a nut 7 having a semi-sphericalnose 8 seated in a depression formed therefor in the jaw 1 as shown inFigs. 1 and 8. This bolt is planed off on faces parallel with thelateral faces of the jaws, and made of a' width to snugly fit saidslots; these smooth sides of the bolt serving to avoid the wear whichwould be caused in the slots by the screw threads; and also by theirsnug fit preserving the parallelism of the transverse lines of the twoaws.

In a socket 10 formed in the butt of the jaw 2 is seated the ball 11terminally mounted on the screw 12, the socket being completed after thesaid ball has been introduced, by the insertion of the plug 13 fixed inplace by a suitable pin 14. The opposite end of the screw 10 is providedwith a handle 15 designed for forcibly turning the same. This screwpenetrates a slot 16 in the butt of the jaw 1, and engages therein a nut17 retained in place therein by a ferrule 18 whose top and bottom sidesare slotted to permit the passage of the screw and the jaws whirledabout on the screw 12 until the butts of the jaws have been brought tothe required distance apart for the work to be fastened together. Thenthe nut 7 which is preferably roughened or milled, is rapidly rotated byrunning a finger along it, until the jaws are brought into perfectcontact with the work. The handle 15 can now be forcibly turned untilthe jaws are made to apply the clamping-pressure re quired, and thenplaced upon the bench with the under surface of the jaw 2 resting fiatthereon.

What I claim as my invention and for which I desire Letters Patent, isas follows, to wit 1. The combination of a pair of clamping jaws, ascrew for pressing their butts apart, a screw pivoted at its end in anintermediate point of one jaw, and a nut turning on the last-named screwexterior to the other jaw and having a half-round nose, the jaw withwhich said nose contacts being correspondingly recessed to receive it.

2. The combination of a pair of clamping jaws, a screw having anoperating handle for pressing their butts apart, a screw pivoted at itsend in an intermediate point of one jaw, and a nut turning on thelast-named screw exterior to the other jaw, the firstnamed screw havingits extremity abutting in the same jaw as that in which the lastnamedscrew is pivoted, and having its operating handle exterior to the otherjaw and hence at the same side as the said nut.

3. The combination of a pair of clamping jaws, a screw for pressingtheir butts apart, a screw pivoted at its end in an intermediate pointof one jaw, and a nut turning on the last-named screw exterior to theother jaw and having a half-round nose, the firstnamed screw and alsothe last-named one being adapted to swing relative to the jaws in aplane coinciding with the latter.

4. The combination of a pair of clamping jaws, a screw having anoperating handle for pressing their butts apart, a screw pivoted at itsend in an intermediate point of one jaw, and a nut turning on the last--named screw exterior to the other jaw and having a half-round nose, bothscrews being adapted to swing relative to the jaws in a plane coincidentwith the latter, and both said nut and the operating handle of thefirst-named screw being at the same side of the jaws.

5. The combination of a pair of clamping jaws, a screw for pressingtogether their operative ends, a screw for pressing apart the butts ofsaid jaws and terminally seated in one of said jaws, and the butts ofthe other jaw being slotted, a nut in said slot for the last-namedscrew, and a ferrule surrounding the said slotted jaw-butt; said nuthaving a pair of trunnions at one end thereof close to one face of saidferrule, both said face and the one opposite thereto being suitablyslotted for receiving the screw, and the ends of said nut beingcylindrical to fit against the inner surfaces of said ferrule besidesaid s ots.

6. The combination of a pair of clamping jaws, and screws for theiradjustment, the screw at the butts of said jaws having a terminal ball,and the butt of one jaw being formed with a groove fitted to said ball,and

having a correspondingly shaped plug fitted to said groove between saidball and the butt end of the jaw, and fastened therein.

In testimony that I claim the foregoing invention, I have hereunto setmy hand this 5th day of October, 1908.

' DAVID A. DUCHARME.

Witnesses:

AUSTIN H. PRENT, FRANK L. Moss.

